The Manhattan Bridge Three Cent Line was a streetcar company that operated cars over the Manhattan Bridge between the boroughs of Brooklyn and Manhattan in New York City. When the bridge was opened on December 31st, 1909, it had tracks which were intended to be used by the subways of the Brooklyn Rapid Transit company (BRT). There were no tracks on either side to connect them to, however. The MBTCL began to run streetcars in 1912, and until 1915 was the only operator of transit over the bridge. In 1915, the trolleys were moved to the upper roadways of the brige, and the BRT subway lines were connected to the former MBTCL's tracks.